Re: 2.5.39 kmem_cache bug

[Andrew Morton <akpm@digeo.com>]

John Levon wrote:
> 
> kmem_cache_destroy() is falsely reporting
> "kmem_cache_destroy: Can't free all objects" in 2.5.39. I have
> verified my code was freeing all allocated items correctly.
> 
> Reverting this chunk :
> 
> -                       list_add(&slabp->list, &cachep->slabs_free);
> +/*                     list_add(&slabp->list, &cachep->slabs_free);            */
> +                       if (unlikely(list_empty(&cachep->slabs_partial)))
> +                               list_add(&slabp->list, &cachep->slabs_partial);
> +                       else
> +                               kmem_slab_destroy(cachep, slabp);
> 
> and the problem goes away. I haven't investigated why.
> 

Thanks.  That's the code which leaves one empty page available
for new allocations rather than freeing it immediately.

It's temporary.  Ed, I think we can just do

	if (list_empty(&cachep->slabs_free))
		list_add(&slabp->list, &cachep->slabs_free);
	else
		kmem_slab_destroy(cachep, slabp);

there?